Method and apparatus for drying printing inks



Jan. 20, 1942.

c. s. JOHNSON El Al. 2,270,654

METHOD AND APPARATUS FOR DRYING PRINTING INKS Filed Dec. 19, 1939 F' I6.I

INVENTORS CARL s. JOHNSON jmcK WALLINE all fwd ATTORNEY Patented Jan. 2,i942 STAT E METHOD AND APPARATUS FOR DRYING ramme S Carl StanleyJohnson, Park Ridge, and Erick E.

Walline,

Chicago, 111., assignors to Enterchemical Corporation, New York, N. Y.,a corporation of Ohio Application December 19,' 1939, Serial No. 309,938

7 Claims.

This invention relates to a method and apparatus for drying printing inkand aims to provide an improved method and apparatus particularlyadapted for drying printing ink or other marking or coating materialthat has been applied to a sheet or web of transparent material.

There are printing inks and marking materials now available that may bequickly dried by the application of heat to the sheet or web upon whichsuch inks have been applied. Experience with these inks has shown thatradiant heat is very efiective as a drying medium when the inks areapplied to opaque material. However, attempts to dry such inks that havebeen applied to transparent materials, such as Cellophane, glassine andthe like, have not been successful because the heat required for properdrying of the ink and applied in the usual manner is sufficient to causedeterioration of the transparent material.

We have discovered that quick drying inks applied to transparentmaterials may be effectively dried with radiant heat without damagingthe transparent material by localizing the heat in the region of theprinted material, and we have devised a novel method and apparatus foraccomplishing this desirable result.

In accordance with our invention, a sheet or web of transparentmaterial, such as Cellophane, glassine and the like, is imprinted withan ink or marking material that may be dried by theapplication ofradiant heat thereto, and said sheet or web isthen passed beneath asource of radiant heat which is directed upon the imprinted surface and,at the same time, the'major portion of the heat is localized in theregion of said sheet or web. We have found that the localization of theheat in the region of the web may be accomplished by arranging a darkcolored, preferably black, background means beneath the transpar-,

ent sheet or web during the period that it is passing beneath the sourceof radiant heat. In the apparatus we have provided for practicing ourour invention will become apparent upon consideration of the followingdetailed description and the accompanying drawing, in which:

Fig. 1 is a diagrammatic side elevational view showing one form ofapparatus with which our improved method of drying printing ink appliedto transparent material may be practiced;

Fig. 2 is a transverse vertical sectional view, taken substantiallyalong the line 2--2 of Fig. 1; and 1 Fig. 3 is a diagrammatic sideelevational view of a modified form of apparatus for practicing ourimproved method.

Referring now to the drawing, and particularly Fig. 1, a web in of anytransparent material, such as Cellophane, glassine or the like, is fedin any convenient manner from a suitable supply roll. I2 to a printingunit It. The printing unit it may be of any suitable type orconstruction, that shown in the present instance being a typographic orletter press unit including a plate or printing cylinder IS, animpression cylinder I8 method, this dark background means may take theform of a dark colored blanket, tympan, back-up sheet or web which isarranged to move with the transparent material being dried; or it maytake the form of a supporting roller or drum for the web, which rolleror drumv is provided The above and other features and objects of {55.the form or an endless belt of any suitable maand any. conventional inkapplying and distributing system 20. The printing cylinder I6 andimpression cylinder l8 are driven in any suitable manner and are adaptedto produce printed impressions 22 (Fig. 2) upon the upper surface of theweb Ill.

The ink used in the printing unit it and applied upon the upper surfaceof the web 10 in this manner is preferably of such acharacter that theprinted impressions may be set or dried by the application of radiantheat thereto. Consequently, following the printing operation, the webill of transparent material, having the printed impressions upon itsupper surface, is led beneath a source, or a plurality of sources, 24 ofradiant heat which are adapted to direct such heat upon the freshlyprinted impressions.

Due to the fact that the web l0 consists of a transparent material, Ithe printed impressions ordinarily would not be dried or set by thisapplication of heat alone, or, if the heat were sufficient for drying,it would cause damage to the transparent material. However, we havefound that if a dark background is provided beneath the web oftransparent material during the application of radiant heat thereto, theheat is localized in the region of the printed web and effective dryingtakes place. Our apparatus therefore includes aback-up web or tympan 25which is arranged to bepositioned beneath the web of transparentmaterial during the drying operation. In the present instance, the web26 takes ized in the region of the printed web of transparent materialwith the result that the printed impressions are effectively dried in ashort period of time and at normal press speeds. With this manner ofoperation, the printing and drying may take place at web speeds up tofive hundred feet per minute. After drying, the

web l0 may be given any suitable subsequent treatment, such as cuttinginto .sheets to be folded or bound, or said web may be rewound on aconventional rewind roll 30.

In Fi 3, we have shown a modified arrangement of the apparatus, in whicha web 32 is fed at the desired speed in any suitable manner from aconvenient supply roll 36 to a printing unit 36 for the application ofprinted impressions to the upper surface thereof. The web '82, with thefreshly printed impressions consisting of an ink that may be dried bythe application of radiant heat thereto,-is led. to a drying apparatus"36 which is adapted to direct radiant heat upon the upper surface ofsaid web. While passing beneath-the drying unit 36, the web 32 is guidedover a suitable web supporting roller or drum 60 which is preferablydriven in unison with the rotating elements of the printing unit 36. Theweb preferably has approximately 180 surface contact with the large drumand the drying unit extends substantially throughout this distance. Inorder that'the printed impression applied upon the transparent materialmay be effectively dried in accordance with" our invention, the roller66 is provided with a black or other suitable dark colored outsidesurface which, as in the form of the invention shown in Fig. l, isadapted to localize the heat in the region of the web; Following dryina,the web may be cut and delivered in sheets or it may be rewound on asuitable rewind roll 42.

Although we have illustrated and described preferred forms of ourinvention as applied to a web'fed press, it will .be understood that thefeatures of our invention-are equally applicable .to sheet fed presseswhere the heat necessary for proper drying may be localized in theregion of the printed sheet of transparent material by the use of adarkcolored slip-sheet or other suitable background means.- Moreover,various changes may be made in the construction and method, and certainfeatures or steps thereof may be employed without others withoutdeparting from our invention or sacrificing any of its advantages.

What we claim is:

l. A method of printing, which comprises applying to the surface of asheet. or web of trans? parent material an ink that may be dried by theapplication of radiant heat thereto, arranging a heat absorbingmeanssubstantially in the plane of the sheet or web, and directing radiantsubstantially in the plane of said sheet or web.

2. A method of printing, which comprises applying to the surface of asheet or web of transparent material an ink that may be dried by theapplication of radiant heat thereto, arranging a dark colored backgroundmeans beneath such sheet or web, and passing the sheetor web togetherwith said background means beneath a source of radiant heat, wherebyheat will be localized in the region of said web so that the printedimpressions may be effectively dried without damage to the transparentmaterial.

3. Apparatus for printing, comprising means for applying to the surfaceof a sheet or web of transparent material an ink that may be dried bythe application of radiant heat thereto; a source of radiant heatarranged adjacent the path of the sheet or web so that heat may bedirected upon the thus printed surface of said web, and heat absorbingmeans disposed substantially in the plane of the sheet or web forcausing the major portion of said heat to be absorbed substantially inthe plane of the sheet or web.

4. Apparatus for printing, comprising means for applying to the surfaceof a sheet or web of transparent material an ink that may be dried bythe application .of radiant heat thereto; a source of radiantpheatarranged adjacent the path of the sheet or web so that heat may bedirected upon the thus printed surface of said web; and means forlocalizing the major portion of the heat in the region of the sheet orweb, said localizing means comprising a dark colored background meanswhich is adapted to be positioned beneath the web of transparentmaterial during its passage beneath the radiant heating means.

5. Apparatus for printing, comprising means for applying to the surfaceof a sheet or web of transparent material an ink that may be dried bythe application of radiant heat thereto; supporting means having a blackoutside surface over which the web may be passed; and.

radiant heating means disposed above said supplying to the surface of asheet or web of transparent material an ink that maybe dried by theapplication of radiant heat thereto, ar-

heat upon the printed surface therebyi'causing ranging a heat absorbingmeans beneath the sheet or web but substantially in the plane thereofand directing radiant heat upon the printed' surface thereby causing themajor portion of said heat to be absorbed in a plane adjacent to planeof the sheet or web and from which said sheet or web may be heated byconduction.

7. Apparatus for printing, comprising means for applying to thesurface'of a sheet or web of transparent material an ink that may bedried by the application of radiant heat thereto; a source of radiantheat arranged adjacent the path of the sheet orweb so that heat may bedirected upon the thus printed surface of said sheet or web; and anendless belt arranged below said source of heat and said sheet or web inposition to contact the sheet or web during its passage beneath thesource of heat and having a surface which is adapted to absorb radiantheat.

' C. STANLEY JOHNSON.

ERICK E. WAILIINE.

